Method of preventing jute staining



United States Patent METHOD OF PREVENTING JUTE STAINING David C. T. Yao, Julian J. Hirshfeld, and Bertie J.

Reuben, Decatur, Ala., assignors to Monsanto Company, St. Louis, Mo., a corporation of Delaware No Drawing. Filed Jan. 6, 1965, Ser. No. 423,859 US. Cl. 8--21 26 Claims Int. Cl. D06p 3/84 This application relates to a method for preventing the discoloration of synthetic fibers when dyed in the presence of jute and, more particularly, to a method for applying salts of zirconium to jute'containing fabrics so as to reduce the staining characteristics thereof.

In the making of some carpets, the surface or pile fiber, such as wool, nylon, acrylic-based fibers, or the like, are tufted into a jute scrim or backing. They are dyed a suitable color by immersing the same in a dye beck, this being the most economical method, although dyed carpets can also be obtained by dyeing the surface fibers before tufting; however, this leads to larger inventory and subsequently higher prices. In the piece dyeing of carpets having synthetic pile, such as, polyamides or polyacrylics, it is desirable for the pH of the dye bath to be below 7.0 for above that figure, certain classes of dyes do not have an affinity for the synthetic fibers; however, low pH dyeing is generally not practical since at low pH values, the jute excretes pectins which stain a white nylon pile carpet a medium shade of beige. At high pH values, the pectins which comprise approximately 24 percent by weight of the jute do not have the tendency to leave the jute, fiber, and therefore, do not discolor the synthetic carpet pile.

It has been found that when zirconium salts are added to the dye bath, jute staining is greatly reduced thereby leaving the pile fibers clear and white; also improved is the brilliancy and depth of the dyeing. The exact explanation for the above-disclosed phenomenon is at this time not known; presumably, the zirconium salt either hydrolyze the pectins or form insoluble complexes or compounds therewith thereby preventing jute staining. The improvements by using the method are obvious, for now it is possible to acid dye or disperse dye carpets having synthetic tufts and jute backing without having the carpets being discolored by the reddish-brown pectins. Also, this method of treatment does not adversely affect the feel or drape of the treated carpet and, furthermore, it actually increases the dye uptake of the synthetic pile.

The zirconium salts may be applied to the jute backing itself or to the finished carpet; in either case, however, it must be applied before dyeing. It is not necessary that the jute backing be tufted upon the application of the zirconium salts, for the jute backing may be treated with a zirconium salt prior to tufting. Where it is known that a particular quantity of jute backing is to be used as a carpet scrim, it is advantageous to treat before tufting in order to save the amount of zirconium salts which would be absorbed or collected by the synthetic pile fibers. However, it is not always known which batch or quantity of jute backing is to be used for a particular type carpet and in such circumstances, this process may be delayed until after the jute backing has been tufted with the synthetic yarn.

The primary object of this invention is to provide a method for neutralizing the dyeing properties of pectins which are included in the chemical make-up of jute.

Another object of this invention is to provide a method for reducing the discoloration of synthetic fibers during the dyeing operation due to their association with the jute backing.

A further object of this invention is to provide a method for dyeing carpets being comprised of a jute scrim and synthetic tufting at low pHs without the synthetic fibers being stained by the pectins which leak from the jute.

These and other objects of this invention will be obvious from the detailed description and examples which appear hereafter.

In general, the objects of this invention are accomplished by a process which comprises impregnating jute or the textile article containing jute with an acidic aqueous solution containing zirconium in either of its valence states and additionally in a preferred embodiment of this invention, a nitrogen-containing organic or inorganic base. The impregnating solution is maintained at a pH value of from about 2 to less than about 7. The temperature of the solution is maintained at from about F. to about 212 F., the preferred operating temperature being within the range from about F. to about 212 F. The substrate is immersed in the impregnating solution for a time ranging from about 10 minutes to about 90 minutes, preferably for 30 minutes.

In general, the solutes (zirconium salt, nitr0gen-containing base and the acid employed to adjust the pH) will be dissolved in an amount of water necessary to give the ratio (weight of go0ds)/(weight of water) a value from about 8 to about 33. The actual concentration of the treating bath is not critical, however, for certain processes, it is obvious that certain concentrations perform more efficiently than others. The solute content of the treating solution is most conveniently expressed as a percentage by weight, based on the weight of the textile article being treated. So expressed, the zirconium salt is employed in an amount from about 1 percent to about 7 percent with about 5 percent representing the generally preferred amount.

It is not known what function the nitrogen-containing salts play in neutralizing the discoloring effects of the jute; however, as the examples will show, there is a synergistic action between the zirconium containing salt and the nitrogen-containing salt to produce a solution which better destroys the discoloring properties of the pectin-containing jute. Many nitrogen-containing compounds may be used in combination with the zirconium salt such as, hydroxylamine, pyridine, ammonia, or derivatives thereof; however, it was found that hydroxylamine sulfate generally has the properties which are desired for this process and do not adversely affect either the jute or the synthetic fibers having been tufted therein. The amount of hydroxylamine, sulfate or other nitrogen-containing compounds may vary with the hydroxylamine sulfate being added to the bath in the amount of from 1 percent to 4 percent based on the weight of the fabrics to be treated with about 3 percent being generally preferred. The quantity of either the organic or inorganic nitrogencontaining base employed in this method is an amount equivalent from about 0.1 percent to about 0.4 percent of ammonia, the preferred amount being about 0.2. percent.

The mechanism of carrying out the treatment provided by this invention are not critical. That is, the article to be treated may be entered into a cold treating bath and the bath thereafter raised to treating temperature or it may be entered directly into a heated treating bath. The treatment is to precede dyeing; however, in some instances the treatment may be combined with the dyeing operation if the latter is carried out within a suitable pH range. The preparation of the impregnating solution itself involves merely the dissolving in the requisite amount of water the zirconium salt and nitrogen-containing organic or inorganic base, or a salt thereof, together with the amount of acid needed to adjust the solution to the desired pH value. The impregnating solution may also be made up while the textile article is immersed in the water to be employed. However, it is preferred that the solution be prepared prior to the impregnation.

While in practice it will be found most convenient to carry out the impregnation of the textile article in an exhaust bath, the treating solution may be applied to the article by padding, spraying, roll application, as will be evident to those skilled in the art.

Any soluble salt of zirconium may be employed in the practice of the invention. Zirconium acetate is particularly suitable because of considerations of cost and the fact that its aqueous solution is only mildly acidic so that the adjustment of the pH of the final impregnating solution to the desired value is facilitated. Final adjustment of pH may be or about with any suitable soluble inorganic or organic acid, such as sulfuric acid, hydrochloric acid, phosphoric acid, formic acid, acetic acid, or the like which is compatible with synthetic fibers, the jute and the solutes.

As hereinbefore stated, the nitrogen-containing bases are considered as either organic or inorganic derivatives of ammonia. In addition to ammonia itself, the class of inorganic derivatives includes such materials as hydrazine, hydroxylamine, ammonium carbonate, and ammonium carbamate. The organic nitrogen-containing bases related to above are those which include alkyl hydrazines, alkyl hydroxylamines, and the amines. The latter embraces primary, secondary, and tertiary amines as well as quaternary ammonium compounds. The substitnent groups in the amines may be alkyl, aryl, arylalkyl, alkaryl, aromatic heterocyclic groups or combinations thereof. Additionally, as in pyridine, the amines nitrogen may form part of a heterocyclic structure. The substituent groups of the amines may carry other reactive groups as in the case of monoethanol amines, glycine or amino acetic acid, para-aminobenzoic acid and the like. Polyamino compounds such as ethylene diamine and guanidine are Within the definition of the organic nitrogen-containing bases.

The nitrogen-containing base may be introduced into the bath in the form of a soluble salt.

The following examples together with comparative test results shown therein illustrate the preferred procedure to be followed in accordance with this invention, however, it should be understood that the examples are illustrative only and not exclusive.

EXAMPLE I A swatch of jute carpet backing was treated for 30 minutes at the boil with 5 percent zirconium acetate (22 percent solution), 3 percent glacial acetic acid and 3 percent hydroxylamine sulfate (all percents expressed on the weight of the goods). The test pieces were then rinsed and dried after which the nylon pile was tufted therein. This carpet fabric was then immersed for 60 minutes in a blank dye bath which was maintained at a temperature of approximately 212 F., the pH of which was 4.5. Thereafter, they were thoroughly rinsed and dried.

The reflectance of the treated test pieces was determined by the method described in American Dyestutf Reporter, vol. 45, No. 7, Marchl956, pp. 190202. The reflectance of the carpet sample before it was dyed was 66, this being the control sample, and the reflectance of the carpet sample after it was blank dyed was 59, the difference being 7 which represents the extent of the jute staining of the nylon. A nylon carpet sample which was not treated with the zirconium acetate but which was blank dyed as in the first sample, had a reflectance of only 46, a difference in reflectance between the untreated carpet sample and the control carpet sample was 20. It can be easily seen that by treating the jute backing with a zirconium containing salt, the reflectance of the carpet is greatly increased thereby and approaches that of the control sample.

All synthetic fibers tested, such as, nylon, acrylic-based fibers, polyester and the like, have the same affinity for the pectins at low pHs and henceforth, nylon will be used in the carpet samples as the standard.

EXAMPLE II The method of Example I was followed with the exception that zirconium acetate was added to the treatment bath in the amount of 3 percent based on the weight of the goods to be treated, 1.8 percent of glacial acetic acid was added based on the weight of the goods and 1.8 percent of hydroxylamine sulfate wasadded based on the weight of the goods. After blank dyeing the carpet samples showed a reflectance of 55 which is a diflerence of 11 when compared with the control sample which has a reflectance of 66. It can be seen that at the lower concentrations of additives, the reflectance is not as good as at higher concentrations; however, the results here are still acceptable.

EXAMPLE III The method of Example I was followed with the exceptions that the pH of the treatment bath was adjusted to 4.2 and the amount of additives was reduced to 1 percent of zirconium acetate, 0.6 percent of glacial acetic acid and 0.6 percent of hydroxylamine sulfate all based on the weight of the goods. The reflectance here was 54 which indicates a slight drop from the previous example where more zirconium and additives were used. However, with the difference only being 12 between this sample and the control sample, this method still comes within an acceptable range and may be used especially where the additives are to be kept at low concentrations. The economic advantages gained by using the concentration as disclosed in this example are apparent.

EXAMPLE IV The method of Example I was followed with the exception that the pH of the bath was 4.6 and only 5 percent of zirconium acetate and 3 percent of hydroxylamine sulfate based on the weight of the goods were added to the treatment bath. By not adding the acetic acid the pH of the system was increased which for some methods would be acceptable, however, for acid dyeing in particular, a low pH is desired. Where a low pH is not desired this method is highly acceptable for the reflectance was 58 which means only a difference of 8 between that and the control which was 66. It can be seen that the acetic acid only slightly affects the reflectance of the samples and this was probably caused by the reduction in pH and not the particular acid itself, meaning that any acid which is compatible with the additives as well as the fabric and jute may be used in this system.

EXAMPLE V The method according to Example I was followed with the exception that the pH of the treatment bath was adjusted to 3.8 and 5 percent zirconium acetate and 3 percent of glacial acetic acid both based on the weight of the goods was added to the bath. The treated samples had a reflectance of 58 which is a difference of 8 when compared with the control which is 66. It is to be noted that the hydroxylamine sulfate was not added in this example; therefore, it can be seen that the hydroxylamine sulfate combines to increase the reflectance only 1. Although 1 degree does not seem to be a significant amount, it is visible to the naked eye.

EXAMPLE VI The method of Example I was followed with the exception that the pH was adjusted to 3.7 and Zirconium acetate, the pectin hydrolizing agent, was not added to the treatment bath. The reflectance was only 42 which is a differential of 24 between this sample and the control sample. It can be seen that the pectins readily discolored the synthetic fibers which were tufted into the jute backing and the addition of the hydroxylamine sulfate and the acetic acid to the treatment bath made no appreciable difference in the staining characteristics of the pectins.

When compared with Example I, it can readily be seen that the zirconium containing salts are the active ingredients and the hydroxylamine sulfate and the acetic acid act only to enhance the stain preventing characteristics of the zirconium containing salts.

EXAMPLE VII The method used in this example proceeds according to that of Example I with the exceptions that the pH of the treatment bath in this example was adjusted to 4.1 and 5 percent based on the Weight of the goods of zirconium acetate only was added to the treatment bath. With only zirconium acetate, the carpet samples showed a reflectance of 57 which is a differential of 9 between that and the control sample.

The observations which can be made from the above examples show that the five percent level of zirconium acetate is the best, that zirconium acetate is definitely the stain preventing agent in the composition and that the addition of acetic acid and hydroxylamine sulfate individually to zirconium acetate increase the reflectance thereof, however, the greatest increase in reflectance is achieved when both acetic acid and hydroxylamine sulfate is added with the zirconium acetate at a ratio of 5 percent, 3 percent based on the weight of the goods.

EXAMPLE VIII The method used in this example proceeds according to that of Example I with the exceptions that the pH of the treatment bath in his example was 1.75 and 5 percent based on the weight of the goods of sodium zirconium sulfate Only was added to the treatment bath. With only sodium zirconium sulfate, the carpet sample showed a reflectance of 54 which is a differential of 12 between that and the control sample.

EXAMPLE IX The method of Example I was followed with the exceptions that the pH of the treatment bath was 2.1 and that sodium zirconium sulfate was added to the treatment bath in the amount of 5 percent based on the weight of the goods to be treated, 3 percent of glacial acetic acid was added based on the weight of the goods and 3.0 percent of hydroxylamine sulfate was added based on the weight of the goods after blank dyeing, the carpet samples showed a reflectance of 56 which is a differential of 10 when compared with the control sample.

EXAMPLE X The method used in this example proceeds according to that of Example I with the exceptions that the pH of the treating bath in this example was 2.0 and 3.5 percent based on the weight of the goods of zirconium oxchloride only was added to the treatment bath. With only zirconium oxchloride, the carpet sample showed a reflectance of 62 which is a differential of 4 between that and the control sample.

EXAMPLE XI The method of Example I was followed with the exception that the pH of the treating bath was 2.2 and that zirconium oxchloride was added to the treatment bath in the amount of 5.0 percent based on the weight of the goods to be treated, 3.0 percent of glacial acetic acid was added based on the weight of the goods and 3.0 percent of hydroxylamine sulfate was added based on the weight of the goods. After blank dyeing, the carpet sample showed a reflectance of 55 which is a differential of 11 when compared with the control sample.

EXAMPLE XII The method used in this example proceeds according to that of Example I with the exceptions that the pH of the treatment bath in this example was 2.6 and 5 percent based on the weight of the goods of zirconyl chloride only was added to the treatment bath. With only zirconyl chloride the carpet sample showed a reflectance of 59 which is a differential of 7 between that and the control sample.

EXAMPLE XIII The method of Example I was followed with the exceptions that the pH of the treatment bath was 3.0 and that zirconyl chloride was added to the treatment bath in the amount of 5 percent based on the weight of the goods to be treated, 3.0 percent of glacial acetic acid was added based on the weight of the goods and 3.0 percent of hydroxylamine sulfate was added based on the weight of the goods. After blank dyeing, the carpet sample showed a reflectance of 55 which is a differential of 11 compared with the control sample.

EXAMPLE XIV The method used in this example proceeds according to that of Example I with the exception that the pH of the treating bath in this example was 7.3 and 5 percent based on the weight of the goods of ammonium zirconyl carbonate only was added to the treatment bath. With only ammonium zirconyl carbonate, the carpet sample showed a reflectance of 58 which is a differential of 8 between that and the control sample.

EXAMPLE XV The method of Example I was followed with the exceptions that the pH of the treatment bath was 4.4 and that ammonium zirconyl carbonate was added to the treatment bath in the amount of 5 percent based on the weight of the goods to be treated, 3.0 percent of glacial acetic acid was added based on the weight of the goods and 3.0 percent of hydroxylamine sulfate was added based on the weight of the goods. After blank dyeing, the carpet sample showed a reflectance of 57 which is a differential of 9 when compared with the control bath sample.

As many different embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments disclosed herein.

We claim':

1. A method for preventing the jute staining of synthetic fibers at pHs ranging from 2 to about 7 comprising the steps of impregnating said jute with an acidic aqueous solution containing as solutes from about 1 to about 7 percent of a zirconium salt from about 1 to about 4 percent of hydroxylamine sulfate, said percentages being based on the weight of the article, and acetic acid, said solution being maintained at a temperature of from about 100 F. to about 212 F., and maintaining intpregnating contact between said article and said solution for from about 10 minutes to about minutes.

2. The method of claim 1 wherein said zirconium salt is sodium zirconium sulfate.

3. The method of claim 1 wherein said zirconium salt is sodium zirconium sulfate, and said solution contains 3 percent of acetic acid and 3 percent of hydroxylamine sulfate, said percentages being based on the weight of the article.

4. The method of claim 1 wherein said zirconium salt is zirconium oxchloride.

5. The method of claim 1 wherein said zirconium salt is zirconium oxchloride, and said solution contains 3% of glacial acetic acid and 3 percent of hydroxylamine sulfate, said percentages being based on the weight of the article.

6. The method of claim 1 wherein said zirconium salt is zirconyl chloride.

7. The method of claim 1 wherein said zirconium salt is zirconyl chloride, and said solution contains 3 percent of glacial acetic acid and 3 percent of hydroxylamine sulfate, said percentages being based on the weight of the article.

8. The method of claim 1 wherein said zirconium salt is ammonium zirconyl carbonate.

9. The method of claim 1 wherein said zirconium salt is ammonium zirconyl carbonate, and said solution contains 3 percent of glacial acetic acid and 3 percent of hydroxylamine sulfate, said percentages being based on the weight of the article.

10. The method of claim 1 wherein said zirconium salt is zirconium acetate.

11. The method of claim 1 wherein said zirconium salt is zirconium acetate, and said solution contains 3 percent of acetic acid and 3 percent of hydroxylamine sulfate, said percentages being based on the weight of the article.

12. In the process wherein synthetic fibers are tufted into a jute backing and thereafter dyed by immersion in a dyebath, the improvement comprising impregnating said jute with an aqueous solution containing as a solute a zirconium salt, said impregnation being accomplished prior to dyeing, whereby jute staining of synthetic fibers at low acidic pHs is prevented.

13. In the process wherein synthetic fibers are tufted into a jute backing and thereafter dyed by immersion in a dyebath, the improvement comprising impregnating said jute prior to dyeing with an acidic aqueous solution containing as a solute a zirconium salt, whereby jute staining of synthetic fibers at a pH value of from about 2 to less than about 7 is prevented.

14. In the process whereby synthetic fibers are tufted into a jute backing and thereafter dyed by immersion in a dyebath, the improvement comprising impregnating said jute prior to dyeing with an acidic aqueous solution containing as a solute a zirconium salt in concentrations ranging from 0.5% to 7% based on the weight of the article, whereby jute staining of synthetic fibers at a pH value of from about 2 to less than about 7 is prevented.

15. The improvement of claim 14 wherein the zirconium salt is zirconium acetate.

16. The improvement of claim 14 wherein said impregnation of said jute is accomplished in the presence of said synthetic fibers.

17. In the process wherein synthetic fibers are tufted into a jute backing and thereafter dyed by immersion in a dyebath, the improvement comprising the steps of impregnating said jute prior to dyeing with an acidic aqueous solution containing a zirconium salt as a solute in concentrations ranging from about 1% to about 7%, based on the weight of the jute, said solution being maintained at a temperature of from about 100 F. to about 212 F., and maintaining impregnating contact between said jute and said solution for from about to about 90 minutes, whereby jute staining of synthetic fibers at pHs ranging from about 2 to about 7 is prevented.

18. The method of claim 17 wherein the zirconium salt is zirconium acetate.

19. The method of claim 17 wherein said zirconium salt is sodium zirconium sulfate.

20. The method of claim 17 wherein zirconium salt is zirconium oxychloride.

21. The method of claim 17 wherein said zirconium salt is zirconyl chloride.

22. The method of claim 17 wherein said zirconium salt is ammonium zirconyl carbonate.

23. The method of claim 17 wherein said impregnation of said jute is in the presence of said synthetic fibers.

24. In the process wherein synthetic fibers are tufted into a jute backing and thereafter dyed by immersion in a dyebath, the improvement comprising impregnating said jute, prior to dyeing, with an acidic aqueous solution containing as solutes a zirconium salt and a material selected from the group consisting of an organic and inorganic nitrogen-containing base and salts thereof.

25. The method of claim 24 wherein the zirconium salt is zirconium acetate and the nitrogen-containing base is hydroxyl amine sulfate.

26. In the process wherein synthetic fibers are tufted into a jute backing and thereafter dyed by immersion in a dyebath, the improvement comprising impregnating said jute, prior to dyeing, with an acidic aqueous solution containing as solutes from about 1 to about 7% by weight of the article of a zirconium salt, a material selected from the group consisting of organic and inorganic nitrogencontaining bases and salts so as to provide nitrogen in the equivalent amount of from about 0.1 to about 0.4% by weight of the article of ammonia, and an acid being compatible therewith, said solution being maintained at a temperature of from about 100 F. to about 212 F., and maintaining impregnating contact between said article and said solution for from about 10 to about minutes, whereby jute staining of synthetic fibers at pHs ranging from about 2 to about 7 is prevented.

References Cited UNITED STATES PATENTS 2,328,431 8/1943 Doser et al. 17-169 X 2,323,387 7/ 1943 Edelstein 117--92 X 2,361,830 10/1944 Edelstein 117169 X 2,424,262 7/ 1947 Wainer 117136 X 2,482,816 9/1949 Van Mater 1l7l43 X 2,535,022 12/1950 Swanson 117169 X 2,734,835 2/1956 Florio et al 117169 2,819,754 1/1958 Feigley 117--140 X 3,031,335 4/1962 Segal et al 117-152 X 3,058,850 10/1962 Sell 11776 X 3,183,149 5/1965 Gonzales et a1. 1l7l43 X WILLIAM D. MARTIN, Primary Examiner.

H. J. GWINNELL, Assistant Examiner.

US. Cl. X.R. 

1. A METHOD FOR PREVENTING THE JUTE STAINING OF SYNTHETIC FIBERS AT PH''S RANGING FROM 2 TO ABOUT 7 COMPRISING THE STEPS OF IMPREGNATING SAID JUTE WITH AN ACIDIC AQUEOUS SOLUTION CONTAINING AS SOLUTES FROM ABOUT 1 TO ABOUT 7 PERCENT OF A ZIRCONIUM SALT FROM ABOUT 1 TO ABOUT 4 PERCENT OF HYDROXYLAMINE SULFATE, SAID PERCENTAGES BEING BASED ON THE WEIGHT OF THE ARTICLE, AND ACETIC ACID, SAID SOLUTION BEING MAINTAINED AT A TEMPERATURE OF FROM ABOUT 100*F. TO ABOUT 212*F., AND MAINTAINING IMPREGNATING CONTACT BETWEEN SAID ARTICLE AND SAID SOLUTION FOR FROM ABOUT 10 MINUTES TO ABOUT 90 MINUTES. 